Wire tensioning apparatus

ABSTRACT

An apparatus for use on a wire winding machine to apply tension and to accurately indicate the tension in the wire as it is pulled therethrough even where the pull on the wire fluctuates rapidly.

[451 Sept. 24, 1974 United States Patent [191 Brown FOREIGN PATENTS OR APPLICATIONS WIRE TENSIONING APPARATUS [76] Inventor:

Maurice H. Brown, PO. Box 367, Palos Heights, 111. 60463 Oct. 3, 1973 1,101,480 1/1968 Great Britain.................. 242/155 R [22] Filed:

Primary Examiner-Stanley N. Gilreath [211 App! 403112 Attorney, Agent, or Firm1(inzer, Plyer, Dorn &

McEachran [57] ABSTRACT An apparatus for use on a wire winding machine to apply tension and to accurately indicate the tension in the wire as it is pulled therethrough even where the pull on the wire fluctuates rapidly.

3 Claims, 3 Drawing Figures [52] [1.8. 242/155 R, 242/148 [51] Int. B65h 59/16, B65h 59/40 [58] Field of Search...... 242/155 R, 148, 156, 156.2

[56] References Cited UNITED STATES PATENTS 1,626,658 5/1927 Anderson...........................242/148 1,946,313 2/1934 Daniels 242/l56.2

WIRE TENSIONING APPARATUS SUMMARY OF THE INVENTION This invention relates generally to wire winding machines, such as transformer or coil winding machines, and more particularly to apparatus for use on such machines to apply tension and to indicate the amount of tension in a wire being pulled therethrough.

A primary object of this invention is to provide an apparatus which accurately indicates the tension being applied to a wire being pulled through the apparatus especially in situations where the amount of pull on the wire fluctuates rapidly due to the shape of the object around which the wire is being wound.

Other objects may be found in the following specification, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated more or less diagrammatically in the following drawings wherein:

FIG. 1 is a front side elevational view of the wire tensioning and tension indicating apparatus of this inventron;

FIG. 2 is a rear side elevational view of the apparatus of FIG. 1; and

FIG. 3 is an end elevational view of one of the sheaves.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings show the invention embodied in a tensioning and tension indicating apparatus 11 which includes a frame 13, a clutch type friction applying or tensioning assembly 15, a band brake tensioning assembly 17, a tension indicating assembly 19 and a wire take-off sheave .21.

A wire 27 is shown being pulled through the apparatus by the winding action of a bobbin or spool 29 driven by a suitable winding machine, not shown.

The wire 27 is shown first entering the clutch-type friction applying member which is formed by a fixed friction plate 31 and a movable friction plate 33. The fixed friction plate may be mounted to the frame by any suitable means. The movable plate 33 is mounted to the frame for movement towards and away from the plate 31 by a suitable threaded member 35 having an enlarged head portion 37. The threaded member 35 extends through the fixed friction plate 31 and the frame 13 and a spring (not shown) is positioned between the frame and the enlarged head portion 37 to yieldingly urge the movable plate towards the fixed plate. One or both of the plates 31 and 33 may be provided with a liner element (not shown) which is formed of felt or other suitable materials for frictional engagement with the wire 27. The force of frictional engagement between the wire 27 and the plates 31 and 33 may be varied by varying the depth of engagement of the threaded member 35 with the frame 13.

The band brake tensioning assembly 17 includes a grooved wheel 45 which is rotatably mounted on the frame 13. An elastic O-ring 47 may be installed in the groove 49 of the grooved wheel in the manner described in US. Pat. No. 3,520,492 to prevent slippage of the wire 27.

The band brake wheel 45 is provided with a circumferential brake surface 51 which is axially displaced from the groove 49 of the wheel. A friction brake band 53 is draped around the circumferential brake surface 51 and is attached at one end to the frame 13 and at its other to a brake operating arm 55 by lugs 57 and 59, respectively.

The brake operating arm 55 is rotatably attached to the frame 13 in any suitable manner. For convenience, the brake operating arm is mounted on the same support as the grooved wheel 45. When the brake operating arm 55 is moved in a clockwise direction as viewed in FIG. 2, the friction brake band 53 is brought into contact with the brake surface 51. The brake operating arm is biased in a clockwise direction as viewed in FIG. 2 by a spring 61 connected to a lug 63 formed on the brake operating arm on the opposite side of the axis of rotation of the arm from the lug 59. The opposite end of the spring 61 is attached to a threaded leg 65 of a generally U-shaped member 67 mounted on the frame 13. The U-shaped member has a second leg 69 with both legs extending through openings in the frame. An adjustment nut 71 threadably engages the threaded leg 65 at a position outwardly of the frame so that rotation of the adjustment nut advances or retracts the threaded leg 65 to increase or decrease a clockwise bias applied to the brake operating arm 55. A brake release spring 73 connected to the lug 63 in the frame biases, the arm 55 in a counterclockwise direction as viewed in FIG. 2 to release the friction band from engagement with the brake surface upon relaxation of tension in the spring 61.

A double grooved sheave 77 is rotatably mounted on the free end of the brake operating arm outwardly of the grooved wheel 45. While the sheave is shown having two separate grooves, it should be understood that two separate sheaves, fastened to each other so as to rotate together, could be substituted for the double grooved sheave.

The tension indicating assembly 19 includes a cantilevered leaf spring assembly 81, which may be made in segments, attached at one end of the frame 13. A single grooved sheave 83 is rotatably mounted at the free end of the cantilevered spring assembly.

The frame 13 includes an arm 85 which generally parallels the cantilevered spring assembly 81. The frame arm 85 is formed with an arcuate surface 87 at its outer end which surface carries a force indicating scale 89. A pointer 91 attached to the end of the leaf spring assembly extends over the scale 89 of the arcuate surface 87.

A wire take-off sheave 99 is rotatably mounted on the frame 13 outwardly of and below the double grooved sheave 77 to direct the wire after it leaves one of the grooves of this sheave. A wire retainer disc 101 which may conveniently be formed of felt is attached to an arm 103 which is pivotally and linearly mounted on the frame for movement into and out of contact with the wire take-off sheave 99. This disc functions to retain the wire in wire take-off sheave in the event the tension on the wire is released.

The use, operation and function of this invention are as follows:

In winding wire, thread or other elongated wire-like members on a bobbin or spool to form, for example, a transformer or inductor coil, it is desirable to apply a regulated amount of tension to the wire. The amount of tension to be applied will vary depending on the diameter and the stiffness of the wire.

In applying tension to the wire being wound, it is desirable to provide a device which accurately indicates the amount of tension in the wire, even though the amount of force being applied to pull the wire may be continually fluctuating. Fluctuations may occur when the wire is being wound around a bobbin or spool having square or rectangular cross-section. In previous tensioning and indicating devices, the indicating mechanism would fluctuate or gyrate rapidly as the pulling force applied to the wire varied. The apparatus of this invention solves that problem by directing the wire 27 in a closed loop around the tension indicating sheave 83 and the brake operating arm sheave 77. Through this arrangement of sheaves and wire, the tension reading remains accurate and fluctuations are virtually eliminated as the pulling force on the wire varies. The use of a double groove on sheave 77 prevents the wire from contacting itself and binding as it moves across this sheave in opposite directions.

In the tensioning and tension indicating apparatus of this invention, the wire 27 to be wound is first passed through the clutch-type friction tensioning assembly 15. The wire 27 frictionally engages friction plates 31 and 33 with the plates resisting movement of the wire, thereby tensioning the wire. The force of frictional engagement and thus the amount of tension applied to the wire may be adjusted by compressing or relaxing the spring using the threaded member 35.

Upon leaving the clutch-type friction tensioning assembly 15, the wire 27 is directed around the grooved wheel 45 with the wire usually being wound one and one-half turns around this wheel. An O-ring 47 may be installed in the groove 49 of this wheel in the manner described in US. Pat. No. 3,520,492 in order to provide greater frictional contact between the wire and the grooved wheel.

As the wire 27 is pulled around the grooved wheel 45, the rotation of this wheel and therefore the amount of tension applied to the wire, is controlled by the engagement of the friction brake band 53 with the brake surface 51 of the wheel. The engagement of the friction brake band with the surface 51 is adjusted by adjusting the threaded leg 65 of the U-shaped member 67 and thereby adjusting the pressure that the spring 61 exerts against the brake operating arm 55.

As the wire 27 leaves the groove 49 of wheel 45, it passes through one of the grooves of the double grooved sheave 77 and then up and over the sheave 83 attached to the cantilevered leaf spring assembly 81. The wire then passes down and under the other groove of the double grooved sheave 77 and then over the wire take-off wheel 99. The wire thus forms a closed loop around the sheaves 77 and 83.

As the bobbin or spool 29 is wound, thereby pulling the wire 27 through the apparatus, the tension on the wire applied by the tensioning assemblies 15 and 17 exert a force on leaf spring mounted sheave 83 which causes a proportionate deflection in the leaf spring and a corresponding movement of the indicator or pointer 91. Suitable indicia of the force scale 89, in cooperation with the indicator, enables continuous visual ascertainment of the amount of tension in the wire 27. The closed loop wire between the indicator sheave 83 and the brake arm operating sheave 77 limits fluctuation of the pointer as the amount of force applied to the wire varies.

I claim: l. A device for applying tension to a continuous wirelike member being drawn therethrough including:

a frame,

a grooved wheel mounted on said frame,

a friction applying means mounted on said frame adjacent said wheel, a brake surface associated with said grooved wheel,

a band brake operating arm pivotally mounted intermediate its ends on said frame,

a brake band connected to said frame and to said arm for movement into and out of braking engagement with said brake surface upon pivotal movement of said arm,

means connected to one end of said operating arm for biasing said arm to move said band brake into braking engagement with said brake surface,

a double grooved sheave mounted on said operating arm at the end opposite that of said biasing means,

a scale having an indicia bearing surface mounted on said frame,

a leaf spring cantilevered from said frame,

a pointer carried by said leaf spring for movement with said leaf spring and positioned overlying said indicia bearing scale surface thereby enable continuous visual ascertainment of the amount of tension in said wire-like member, and

a sheave attached to the free end of said leaf spring, said wire-like member passing through said friction applying means, around said grooved wheel and around said operating arm sheave and said leaf spring sheave to form a closed loop so that tension in the wire pulls said sheaves towards each other.

erating arm sheave. 

1. A device for applying tension to a continuous wire-like member being drawn therethrough including: a frame, a grooved wheel mounted on said frame, a friction applying means mounted on said frame adjacent said wheel, a brake surface associated with said grooved wheel, a band brake operating arm pivotally mounted intermediate its ends on said frame, a brake band connected to said frame and to said arm for movement into and out of braking engagement with said brake surface upon pivotal movement of said arm, means connected to one end of said operating arm for biasing said arm to move said band brake into braking engagement with said brake surface, a double grooved sheave mounted on said operating arm at the end opposite that of said biasing means, a scale having an indicia bearing surface mounted on said frame, a leaf spring cantilevered from said frame, a pointer carried by said leaf spring for movement with said leaf spring and positioned overlying said indicia bearing scale surface thereby enable continuous visual ascertainment of the amount of tension in said wire-like member, and a sheave attached to the free end of said leaf spring, said wire-like member passing through said friction applying means, around said grooved wheel and around said operating arm sheave and said leaf spring sheave to form a closed loop so that tension in the wire pulls said sheaves towards each other.
 2. The device of claim 1 in which a second means is provided for biasing said operating arm to urge said brAke band out of braking engagement with said brake surface.
 3. The device of claim 1 in which a wire take off sheave is provided to guide the wire as it leaves said operating arm sheave. 